What should I write about in an essay about The Arctic Biome and Desert Biome?

Something about the Artic Biome And desert biome

For the artic biome you could talk about climate change and how a lot of the ice is melting due to climate change, so complete ecosystems are being destroyed there. (ex: lots of polar bears are slowing starving and losing their habitat). for the desert biome maybe you could talk about a drought somewhere or how the local animals and vegetation handle the climate there

Hydrosphere is the correct answer